Automatic control for internal combustion engines



July 16, 1935.- J CAMPBELL 2,008,577

AUTOMATIC CONTROL FOR INTERNAL COMBUSTION ENGINES Filed Oct. 26, 1931 2 Sheets-Sheet 1 INVEWTOI? JOHN F. CAMPBELL ATJ'UHMS July 16, 1935. J. F. CAMPBELL AUTOMATIC CONTROL FOR INTERNAL COMBUSTION ENGINES 2 Sheets-Sheet 2 Filed Oct. 26, 1931 11v VENTOR JOHN E CAMPBELL ATTORNEY Patented July 16, 1935 UNITED STATES PATENT OFFICE 9 AUTOMATIC CONTROL FOR INTERNAL COMBUSTION ENGINES John F. Campb ell, Dayton, Ohio Application October 2t, 1931, Serial No. 570,994

3 Claims. (01. 123 1os) This invention relates to improvements in means for controlling the admission of fuel to internal combustion engines, and has for its object to provide a device or apparatus that will deliver fuel of a predetermined mixture strength under conditions of varying loads or speeds.

It is an object of this invention to provide control means for internal combustion engines that is responsive to changes in air density at varying altitudes and changes in the pressures in the induction system of the engine so as to maintain the desired predetermined mixture strengths, thereby making a mechanical linkage between the fuel charger and the air throttle unnecessary.

It is also an; object of this invention to provide a control means for internal combustion 'engines for keeping the fuel charger lever in a.

provide for the desired increase charge while cranking.

It is a further object of this invention to proe vide an automatic control for internal combustion engines which makes for simple installation on the unit which it controls and operates.

These and other advantages will appear from the following description taken in connection with the drawings, in which there is shown a preferred embodiment.

Referring to the drawings:

Figure 1 is a view showing a part of the motor ring, a part of the starter; the fuel charger, and an automatic control connectedthereto.

Figure 2 is a longitudinal "section through the automatic control for internal combustion engines.

Figure 3 is a fragmentary section on the line 38 of Figure 2.

Figure 4 is a view of the bracket structure usedin connection with the metallic bellows for operating the helix shaft.

- Figure 5 is an end elevation of Figure 4.

The present automatic control for internal 45 combustion engines is adapted to be used with any engine of the internal combustion typ, but is particularly designed and well adapted for use in connection with airplane engines. In the present drawings .it is-shown in connection with 5 the mounting ring I of an airplane.

On one side of this ring and properly supported in connection therewithis a starter 2 used for starting purposes. Connected with the starter and suitably supported by the ring and the engine supported thereby is a gear reduction box 8 used to house the gearing for connecting the mechanism for operating the fuel or gas delivery and distributing means. The numeral 4 is used to designate the mounting flange of the engine.

,The device is mounted, by preference in the present instance, directly to the unit to be controlled by means of mounting pads 5. The apparatus isshown properly mounted in'its proper surroundings in Figure 1. In Figure 2 there is a longitudinal section. In this section and also in Figure 1 there is shown a fuel charger 6, which may be of any desired and suitable form and character. Extending from a movable part of this fuel charger is a bracket 1, to which one end of a piston rod 8 is attached by means of a pin 9 fitting in a slot III in the bracket 1.

On the inner end of the piston rod 8 is a piston ll working in a cylinder l2, which constitutes an oilpressure cylinder. On the piston is an apron ll projecting in a slot H in one side of the cylinder. l2. Between the piston H and one end of the cylinder I2 is a spring [5. Extending through the front end of the cylinder I2 is an oil inlet l8, which is connected to the oil pressure line from the engine for transmitting oil pressure to the cylinder I2 against the piston H. The position of the piston II in the cylinder depends upon the spring l5 and the oil pressure against the piston, and also upon the, position of a hollow metering valve I 1 located adjacent the cylinder l2 and along the slot l4.

This metering valve has a spiral slot l8 around the metering valve so that in whatever position the metering valve may be the spiral slot I8 will cross at some point the slot I4, so that oil pressure will pass from the cylinder I2 through the two slots into the hollow metering valve, and out through a drain line at the lower end thereof. Whenever the oil passes out through these two slots pressure against the piston is released so that the spring will force the piston toward the oil pressure opening 16 and will force the piston ing between the two slots. If the pressure becomes great this pressure on the piston will cause a larger opening between the twoslots, thereby diminishing the pressure in the cylinder against the springso that the spring moves the piston to reduce the outlet between the two slots, thereby increasing a condition of equilibrium between the spring and the oil pressure.

' to a point that there is left merely a bleed open- At each end of the hollow metering valve are bearings l9-to support this valve so that it may readily rotate for bringing the spiral slot in properposition with relation to the slot I 4 and,

the piston ii. On one end of the hollow metering valve and beyond the bearings thereon is a, pinion meshing with a gear 2| on ashaft 22, This shaft 22 is mounted in bearings 23. To this shaft is suitably attached a helix shaft 24, which has on opposite sides thereof spiral, flat surfaces 25. This helix shaft projects into a pressure chamber 26.

The above descr'ibedshaft 22 and helix shaft 24 are located in one end of the pressure chamber, while in the other end and suitably attached thereto, is a metallic bellows 21. The inner end within the cap member 28, is a cylindrical memher so. This cylindrical member so has holes 3| therein to receive and permit rotative movement of the helix shaft 24 and longitudinal movement of the metallic bellows 21 and brackets 29.

In the cylindrical member are two rollers, one 32 and the other 33, engaging the spiral flat sides of the helix shaft. These rollers are inclined in regard to the axis of .the helix shaft so that each roller engages a spiral flat side so that each roller is seated and held at the normal angle with respect to the side that it engages. By this means it is impossible to move the metallic bellows without consequent angular movement of the helix shaft. In other words,- the arrangement of the rollers with respect to the helix shaft does not permit back lash or false movement. Also, this 75 the injector after the engine has been stopped.

arrangement permits only line contact between the rollers and the helix shaft, which arrangement creates less friction or resisting force to the expansion and contraction of the metallic bellows and. consequent rotation of the helix shaft than any other known arrangement.

In order to permit an adjustment between the shaft 22 and the hollow metering valve the pinion 20 and the gear 2| may be removed and other of these members of relatively different sizes placed thereon by means, of attaching screws or bolts 34. In order to provide an outlet for the oil bled through the slots i4 and i8 there is a bleed outlet 35. There is also an outlet 36 for any oil that may pass by the piston ll into the part of the cylinder occupied by the spring i5. There is also provided an outlet 31 for any oil that may leak out through the upper end of thehollow metering valve.

All of these outlets lead into a pip that conducts the oil back to the inlet side of the oil pump, the outlet side of which is connected to the oil inlet l6. v

In order to operate the fuel charger independ ently of the piston rod 8 there is provided a fuel injector lever 38. This lever may be operated by any suitable hand means, and may be so positioned that all inlets to the cylinders are .cut off. Also, this fuel injection lever may be used for starting purposes. When this lever is in the extreme left-hand position the fuel charger is in such position that the greatest amount of gas is delivered to the cylinders of the engine, whereas if the bracket I is removed to a dotted line posi- 'tion as shown in Figure 2, the gasoline inlets to the engine cylinders are all closed so that. no fuel can be admitted into the cylinders, and in order to admit fuel the fuel injector lever must be moved toward the left-hand, as shown inFigure'2.

The spring l5 serves two purposes, the first being to counteract the oil pressure in the cylinder l2; the other to prevent the delivery of fuel from This acts as a safety device to prevent persons from starting theengine accidentally by cranking the engine with the ignition switch on. The numeral 39 indicates a pressure inlet connecting the metallic bellows expands, thereby moving the brackets 29 along the helix shaft, thereby rotating the shaft and atthe same time rotating the hollow metering valve I1. The rotation of the hollow metering valve changes the position of the slot I8 with regard to the slot l4. If this relative change of position causes the opening between these two slots to be entirely closed, due to the piston and the apron i3, pressure is built up in the cylinder i2 so that the piston is forced against the spring I5. The piston is thus forced against the spring until the point where the two slots intersect is opened. That permits the pressure of the oil to be released by the oil passing into the hollow metering valve.

Any movement of the metallic bellows will cause a movement or rotation of shaft 22 and of the hollow metering valve. This rotation will cause a corresponding movement of the piston i I so that the pressure in the cylinder is adjusted to equalize the pressure of the spring. This movement of the piston varies with the rotation of the helix shaft. This helix shaft rotates due to a variation of pressure in the pressure chamber. Therefore, any variation in the pressure chamber will cause a movement of the piston II, the rod 8, the brackets 1 and the control means for the fuel charger. By this means the fuel is regulated according to the pressure in the pressure chamber 26'. The amount of movement of the piston rod 8 with relation to the rotation of the helix shaft may be varied by varying the relative sizes of the pinion 20 and the gear 2|. This ad- Justment may also be made by changing the incline of the helix of the groove [8 or by changing the angular position of the metallic bellows 21 by rotating it. It will be understood that while in my embodiment shown I have utilized the lubrication pres-1 sure in the engine for circulation through the piston and the valve, any constant or variable pressure of a fluid or gas, whether a part of the engine system or not, may be employed.

It will be further understood that my control device is applicable to any type of mechanism other than an engine, and a pressure-actuated device may be applied and connected to a region 1. In a fuel control apparatus, in combination with an internal combustion engine, a cylinder having an inlet for oil under pressure, a piston in said cylinder adapted to be moved in one direction by the oil pressure in the cylinder, a spring tending to move the piston against the oil pressure, means operated by the movement of the piston .to regulate the delivery of fuel to the engine, and means-operatively connected to the induction system of the engine to provide and aooasw adjustably locate an oil outlet irom the whereby the position oi. the piston in the cylinde is determined. v

2. In combinatioma device ailected by change in pressure, a piston actuated by a fluid. means of supplying a fluid to the piston, a cylinder for receiving and guiding the piston and receiving '3 am a smite mm, up

degreeot pressureinachamberassociatedwith anengine. a cylinder. a piston in said cylinder, means connected to said pistoutor operating said engine.meanstorsiipplyingampplyotiiuidto said cylinder; and a valve operated by said device for regulating the flow of said fluid from the cylinder and cooperating pith the cylinder to adjust'ably locate an outlet from the cylinder therethe cylinder is aflected by said fluid.

JOHN I. CAMPBELL.

try controlling the extent to which the piston oi 10 

